Of course, when it comes to longevity/projection/sillage discussions of any fragrance, everyone's experiences are always different and everyone's perceptions are subjective: Subtle means many different things to many different people. So...take my advice with a grain of salt.
As a lover of Shalimar, in all of its formulations (except for the EDT & the new Parfum Initial), I must start off by saying that the Shalimar being sold now is just not as lovely, full, deep or tenacious as the vintage juice. I'm assuming (you didn't say otherwise) that you bought her 'new' parfum and while this is a lovely version of the scent in it's current modern (re)formulation it has been toned down, the sandalwood in it is (of course) not Mysore, it's been...LVMH'd, for lack of a better word. Nonetheless, it's lovely stuff, a lot more lovely than many of the feminine releases hitting the fragrance counters, but still a shadow of it's former self. So keep this in mind. And if you have the time and desire to do so, start searching for vintage parfum on Ebay, where I have successfully bought bottles for many years. The versions I have are from the sixties (in that black zig-zag pattern box) and it's my favorite.
Now...even vintage parfum is subtle...compared to the EdT, EdP, EdC. So, since she is applying 'new' parfum, it seems to me that to get the most bang for her buck your wife should try the following:
- If she has dry skin, moisturize her body with a scent-free body lotion or cream prior to applying her parfum
- Decant her parfum into an atomizer and spray it on
- Spray away from her neck (she might be fatiguing her nose too quickly with the scent, applying it in an area that is TOO CLOSE to her nose) and instead scent her wrists, crook of her elbows, chest area, back of her neck or even her torso or upper legs - remember scent usually travels up
- Try a light application versus a liberal application to see which one works best for her nose/skin type/nose sensitivity/climate/etc...
- Layer the parfum with Shalimar lotion (or even better the Body Cream) and/or shower with the Shower Gel. There's even Shalimar scented powder. That might be a nice luxurious Xmas gift for her rubegon and it's easy to find these at a discount online. Furthermore, she might try layering the parfum her Shalimar EdP - I do this with the parfum and EdC and it works wonderfully. Just remember she won't have to apply as much, with these layering methods.